As soon as President Donald Trump was sworn in as the 45th president of the United States, at 12:01 p.m. Eastern on Friday, Brig. Gen. William Walker assumed command of the District of Columbia National Guard.

Walker, previously the head of Land Component Command at Joint Force Head Quarters District of Columbia, relieved Maj. Gen. Errol Schwartz, who retired after 40 years in the guard.

"It is an honor and a privilege to serve in this capacity," Walker said in a Friday release. "I look forward to working with the men and women of the D.C. National Guard and to serving our new commander-in-chief."

A week before the inauguration, Schwartz told The Washington Post that the incoming administration had ordered that he turn over his job in the midst of Inauguration Day events.

Schwartz then told the Post that the transition team offered to let him stay on for a few more days after the report went public, but he declined the offer. Unlike state guard organizations, which are led by generals appointed by their governors, the District of Columbia's commanding general is chosen by the president.

Army National Guard Col. Aaron Dean will take over for Walker at JFHQ-DC and Air National Guard Brig. Gen. George Degnon has been named adjutant general, according to the release.

Schwartz, who enlisted in the DC Guard in 1976, had commanded the organization since 2008. He had previously been the deputy commanding general of the DC Guard and the adjutant general of the DC Army National Guard.

Walker will serve in his new post until President Trump appoints a permanent commanding general.